To evaluate if auditors might be helped in determining the chances of fraud if they carefully measure cash flow, samples of midlevel auditors from CPA firms were asked to indicate the chance of material fraud on a scale from 0 to 100 for a case. A random sample of 39 auditors used the cash-flow information. Their mean assessment was 37.69, and the sample standard deviation was 23.36. For an independent random sample of 39 auditors not using the cash-flow information, the sample mean and standard deviation were respectively 48.72 and 26.64. Test at the 10% level the assumption that the population variances were the same for auditors using cash-flow information as for auditors not using cash-flow information against a two-sided hypothesis. Assume the populations are normally distributed. To test the assumption that the population variances for assessments of the chance of material fraud were the same for auditors using cash-flow information as for auditors not using cash-flow information against a two-sided hypothesis, identify the null and alternative hypotheses. Choose the correct answer below. OA. Ho: oso H₁:0² > 0² C. Ho: 0²20² H₁:0² <0² B. Ho: oso H₁:0² <0² D. H₁: o² = 0² 2 H₁:0² #0²

A bridal gown shop owner owns a store in San Francisco and a store in Redwood city. She is trying to figure out if clients tend to spend the same amount at both stores. She takes a random sample of 25 purchases from each store, and find the San Francisco store has a mean amount spent of $2500 with a standard deviation of $1500. The Redwood City store has a mean amount spent of $2000 with a standard deviation of $1000. Use a significance level of 10% to determine if the clients at the two stores spend the same amounts. State:  Plan: Do: Conclude:

In a study examining the relationship between socioeconomic status (SES) and academic achievement among high school students, the researchers collected data on 500 students from varying SES backgrounds. The SES was categorized into low, medium, and high. The academic achievement was measured using GPA scores. The following descriptive statistics were obtained: Mean GPA for low SES students: 2.8 Standard deviation of GPA for low SES students: 0.5 Mean GPA for medium SES students: 3.5 Standard deviation of GPA for medium SES students: 0.3 Mean GPA for high SES students: 4.0 Standard deviation of GPA for high SES students: 0.2 a) Calculate the coefficient of variation for each SES group and interpret the results.

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

The president of an all-female school wants to know if the students at her school studied more or less, on average, than the students at a neighboring all-male school. To find out, she conducted a study. Accordingly, samples were taken at each school with the following results: All female: sample size = 43, mean study time ( hours) = 18.56, standard deviation (hours) = 4.35 All male: sample size = 38, mean study time (hours) =17.95, standard deviation (hours) = 4.87 Calculate the 95% confidence interval for the differences between population means. Use brackets write the final answer [x.xx, x.xx]

The following are the normalized levels of a critical protein in 12 samples of blood: 8.2 , 4.7 , 10.3 , 11.7 , 18.3 , 5.9 , 3.8 , 18.9 , 7.6 , 14.2 , 9.8 , 16.4 Compute the sample mean, the sample median, and the sample standard deviation.

The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures students' study habits and attitudes toward school. The survey yields several scores, one of which measures student attitudes toward studying. The mean student attitude score for college students is about 30, and standard deviation is about 12. A researcher in the Philippines is concerned about the declining performance of college graduates on professional licensure and board exams. She suspects that poor attitudes of students are partly responsible for the decline and that the mean for college seniors who plan to take professional licensure or board exams is less than 30. She gives the SSHA to an SRS of 144 college seniors in the Philippines who plan to take professional licensure or board exams. Suppose we know that the student attitude scores in the population of such students are Normally distributed with standard deviation σ = 12. (a) We seek evidence against the claim that μ = 30. What is the…

In a sample of 351 gamers between the ages of 16-25, the mean number of hours spent gaming per week was 42.5 hours. In a sample of 269 gamers between the ages of 26-40, the mean number of hours spent gaming per week was 43.8 hours. If the population standard deviation for the mean number of hours spent gaming per week is 9.5 for the age group 16-25 and 10.7 for the age group 26-40, test the claim that gamers between the ages of 16-25 spend less time gaming per week than gamers between the ages of 26-40. Assume α=0.03.      Let population 1 be gamers in the age group 16-25 and population 2 be gamers in the age group 26-40. Round the test statistic to two decimal places, and round the p-value to four decimal places.   The test statistic is . The p-value is . Should the null hypothesis be rejected?

According to the Bureau of Labor Statistics, the mean salary for registered nurses in Kentucky was $57,688. The distribution of salaries is assumed to be normally distributed with a standard deviation of $5,879. Someone would like to determine if registered nurses in Ohio have a greater average pay. To investigate this claim, a sample of 192 registered nurses is selected from the Ohio Board of Nursing, and each is asked their annual salary. The mean salary for this sample of 192 nurses is found to be $58,016.005.  1. Completely describe the sampling distribution of the sample mean salary when samples of size 192 are selected. 2. What conjecture has been made? 3. Using the distribution described in part a, what is the probability of observing a sample mean of 58,016.005 or more? 4. Based on the probability found, what conclusion can be reached?